so I tested the new 4.0rc1 on a T530 with coreboot & SeaBios as payload:
It installed perfectly fine, then on first boot I ran into the issue
After installation Grub is loaded, I selected an entry, the screen
remains blank. Reboot after 2-3s.
I managed to fix that by removing the iommu=no-gfx line from the xen
kernel parameters in the grub menu. What exactly did I do with that? So
my Intel GPU now also uses VT-d? Is this a problem?
Anyway it looked like a Xen bug to me.
Then the installer for the 1st time configuration hang at "Executing
Qubes configuration", mouse became unusable --> Reboot.
Installer pops up again, this time it all goes through & surprisingly
quick, xfce starts, yay...
I accidentally click on "One empty panel..." --> hrmpf, ok I get an
empty panel and an empty screen apart from the wallpaper - who needs that?
Trying to find out whether VT-d is enabled on command-line - ah,
qubes-hcl is not installed. -_-
xl info shows virt_caps = hvm_directio, so VT-d seems to work.
Thanks @devs, I will have a deeper look soon!